mailing list

(Often shortened in context to "list") An
electronic mail address that is an alias (or macro, though
that word is never used in this connection) which is expanded
by a mail exploder to yield many other e-mail addresses.
Some mailing lists are simple "reflectors", redirecting mail
sent to them to the list of recipients. Others are filtered
by humans or programs of varying degrees of sophistication;
lists filtered by humans are said to be "moderated".

The term is sometimes used, by extension, for the people who
receive e-mail sent to such an address.

Mailing lists are one of the primary forms of hacker
interaction, along with Usenet. They predate Usenet,
having originated with the first UUCP and ARPANET
connections. They are often used for private
information-sharing on topics that would be too specialised
for or inappropriate to public Usenet groups. Though some
of these maintain almost purely technical content (such as the
Internet Engineering Task Force mailing list), others (like
the "sf-lovers" list maintained for many years by Saul Jaffe)
are recreational, and many are purely social. Perhaps the
most infamous of the social lists was the eccentric bandykin
distribution; its latter-day progeny, lectroids and
tanstaafl, still include a number of the oddest and most
interesting people in hackerdom.

Mailing lists are easy to create and (unlike Usenet) don't
tie up a significant amount of machine resources (until they
get very large, at which point they can become interesting
torture tests for mail software). Thus, they are often
created temporarily by working groups, the members of which
can then collaborate on a project without ever needing to meet
face-to-face.

Requests to subscribe to, or leave, a mailing list should
ALWAYS be sent to the list's "-request" address (e.g.
ietf-request@cnri.reston.va.us for the IETF mailing list).
This prevents them being sent to all recipients of the list
and ensures that they reach the maintainer of the list, who
may not actually read the list.